linux/drivers/leds/leds-lp55xx-common.h
Milo(Woogyom) Kim 10c06d178d leds-lp55xx: support firmware interface
This patch provides additional device attributes which enable
 loading the firmware. ('select_engine' and 'run_engine')
 To run a LED pattern, two parts of driver should be enabled.

 Common features : lp55xx-common
 ===============================
 Firmware interface for loading LED patterns

 Chip specific features : leds-lp5521, leds-lp5523
 =================================================
 Register addresses for loading firmware data
 Register addresses for running selected engine

 Pattern programming sequence
 ============================
 LP55xx chips have three program engines.
 To load and run a LED pattern, the programming sequence is as follows.
 (1) Select an engine number (1/2/3)
 (2) Set engine mode to load
 (3) Write pattern data into selected area
 (4) Set engine mode to run

 This sequence is almost same as the firmware interface.
 (1) Select an engine number               : 'select_engine' dev attribute
 (2) Mode change to load                   : 'loading' of firmware class
 (3) Write pattern data into selected area : 'data' of firmware class
 (4) Mode change to run                    : 'run_engine' dev attribute

 (1) and (4) are device specific features which provide callback functions
 (2) and (3) are common features.

 For example,
 echo 1 or 2 or 3 > /sys/bus/i2c/devices/xxxx/select_engine
 echo 1 > /sys/class/firmware/lp5521/loading
 echo "4000600040FF6000" > /sys/class/firmware/lp5521/data
 echo 0 > /sys/class/firmware/lp5521/loading
 echo 1 > /sys/bus/i2c/devices/xxxx/run_engine

 As soon as 'loading' is set to 0, registered callback is called.
 Inside the callback, the selected engine is loaded and memory is updated.
 To run programmed pattern, 'run_engine' attribute should be enabled.

 Device specific data structure
 ==============================
 o Firmware callback
   load selected engine and update program memory
 o Run engine
   change the engine mode
 o 'engine_idx' and firmware data, 'fw'
   Those are used in the driver internally with callback functions

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
2013-02-06 15:59:28 -08:00

130 lines
3.7 KiB
C

/*
* LP55XX Common Driver Header
*
* Copyright (C) 2012 Texas Instruments
*
* Author: Milo(Woogyom) Kim <milo.kim@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* Derived from leds-lp5521.c, leds-lp5523.c
*/
#ifndef _LEDS_LP55XX_COMMON_H
#define _LEDS_LP55XX_COMMON_H
enum lp55xx_engine_index {
LP55XX_ENGINE_INVALID,
LP55XX_ENGINE_1,
LP55XX_ENGINE_2,
LP55XX_ENGINE_3,
};
struct lp55xx_led;
struct lp55xx_chip;
/*
* struct lp55xx_reg
* @addr : Register address
* @val : Register value
*/
struct lp55xx_reg {
u8 addr;
u8 val;
};
/*
* struct lp55xx_device_config
* @reset : Chip specific reset command
* @enable : Chip specific enable command
* @max_channel : Maximum number of channels
* @post_init_device : Chip specific initialization code
* @brightness_work_fn : Brightness work function
* @set_led_current : LED current set function
* @firmware_cb : Call function when the firmware is loaded
* @run_engine : Run internal engine for pattern
*/
struct lp55xx_device_config {
const struct lp55xx_reg reset;
const struct lp55xx_reg enable;
const int max_channel;
/* define if the device has specific initialization process */
int (*post_init_device) (struct lp55xx_chip *chip);
/* access brightness register */
void (*brightness_work_fn)(struct work_struct *work);
/* current setting function */
void (*set_led_current) (struct lp55xx_led *led, u8 led_current);
/* access program memory when the firmware is loaded */
void (*firmware_cb)(struct lp55xx_chip *chip);
/* used for running firmware LED patterns */
void (*run_engine) (struct lp55xx_chip *chip, bool start);
};
/*
* struct lp55xx_chip
* @cl : I2C communication for access registers
* @pdata : Platform specific data
* @lock : Lock for user-space interface
* @num_leds : Number of registered LEDs
* @cfg : Device specific configuration data
* @engine_idx : Selected engine number
* @fw : Firmware data for running a LED pattern
*/
struct lp55xx_chip {
struct i2c_client *cl;
struct lp55xx_platform_data *pdata;
struct mutex lock; /* lock for user-space interface */
int num_leds;
struct lp55xx_device_config *cfg;
enum lp55xx_engine_index engine_idx;
const struct firmware *fw;
};
/*
* struct lp55xx_led
* @chan_nr : Channel number
* @cdev : LED class device
* @led_current : Current setting at each led channel
* @max_current : Maximun current at each led channel
* @brightness_work : Workqueue for brightness control
* @brightness : Brightness value
* @chip : The lp55xx chip data
*/
struct lp55xx_led {
int chan_nr;
struct led_classdev cdev;
u8 led_current;
u8 max_current;
struct work_struct brightness_work;
u8 brightness;
struct lp55xx_chip *chip;
};
/* register access */
extern int lp55xx_write(struct lp55xx_chip *chip, u8 reg, u8 val);
extern int lp55xx_read(struct lp55xx_chip *chip, u8 reg, u8 *val);
extern int lp55xx_update_bits(struct lp55xx_chip *chip, u8 reg,
u8 mask, u8 val);
/* common device init/deinit functions */
extern int lp55xx_init_device(struct lp55xx_chip *chip);
extern void lp55xx_deinit_device(struct lp55xx_chip *chip);
/* common LED class device functions */
extern int lp55xx_register_leds(struct lp55xx_led *led,
struct lp55xx_chip *chip);
extern void lp55xx_unregister_leds(struct lp55xx_led *led,
struct lp55xx_chip *chip);
/* common device attributes functions */
extern int lp55xx_register_sysfs(struct lp55xx_chip *chip);
#endif /* _LEDS_LP55XX_COMMON_H */